Figure 8.

N-glycosylation increases the protease resistance of the mature CFTR. Limited trypsinolysis of the wt and 2D-CFTR. Isolated microsomes from BHK cells treated with or without 5 µg/ml BFA for 24 h were exposed to trypsin. Proteolytic patterns were visualized by immunoblotting with domain-specific (shown in parentheses) anti-CFTR antibodies. Dashed regions designate putative fragments containing the Ab-specific domains validated previously (Du et al., 2005; Cui et al., 2007). The glycosylation defect provoked increased protease susceptibility of the MSD2 relative to wt in the absence as well as in the presence of BFA. The asterisks designate novel MSD2 degradation intermediate in the 2D-CFTR.